508 -13 Fan Low Speed not working - A/C issue

[northrol]

Hi Martin,
Did not solve it for me either, but in between I managed with diagnose equipment to find and fix a wrong coding for my BSM relais box.
There was a compressor w/out clutch registered instead of my typ with clutch.
Consequently neither compressor nor low-speed fan were working.

I’m sorry to hear that it did not solve your problem either.

As for your issue I can direct to some material that I found on the way.
I can warmly recommend the manual for fault checking with simple equipment, that is one of the best I could find (Gör det själv - jobb på AC).
https://fam-bjork.se/citroen/AC/gds1.html

Thank you! I will look into this asap!

The conditions for running compressor and low speed fan are very complex and include measuring a certain pressure window for the cooling fluid as well as eg. a thermal switch in the cooling water unit.
Also bear in mind that water in the R134a filling can obstruct the system.

Water like condensation? I don’t see how water can get in there but as my car is taking a small amount of coolant since they replaced the timing belt … I don’t see why not. Lol.

I found a wiring diagram for the first generation 508, (Number of the relais in this list is 1508, if that can be of any help).
and a scheme for the fuses and relais of the box that I can pm.

Yes please, I would love that! Thank you so much!

additionally recommended:

(Peugeot 308 AC not working diagnostic repair. PART 1 - 3)
and regarding cable corrosion:
https://www.peugeotforums.com/threads/y ... an.161273/


Hope that can give some clues, good luck!

Guess the "clonk" that you are hearing is when the clutch of the compressor is engaging?
Is it engaging and releasing shortly after whenever you press AC max?

/Marian

Thank you, I will look into this asap.

Yes it is basically at the same time or maybe a second or so after button is pressed the clonk sound comes…

[ozvtr]

The "clonk" is most likely the compressor kicking in. But you need to look at the inner hub of the compressor pulley and see if it spins when the "clonk" happens. Without the compressor engaged, the outer pulley will spin but the inner hub will not.

If the compressor is running then that means there is at least a minimum of refrigerant in the system. However if the system does not cool when the weather is hot that leads me to believe the system is under charged. The condenser fan will run when the "high side" (of the A/C system) pressure gets above a certain point. If the system has a low charge, then the high side pressure will be down and the fan may not come on.

Cold weather may allow enough heat transfer from the evaporator to the condenser to dry the air and de-mist windows...but I'm just making assumptions.

It's possible the blend door in the heater box is not working correctly, but you should be able to select between hot air and ambient and feel the vents change temperature.

You need to get a set of service gauges onto the system to see what the pressures are doing. That will tell you if it's a system problem or an electronic problem. That is...seek professional help.

[Marian]

Hi, just press shortly with a small screwdriver the connection valve of AC. If it is good it responds with a forcefull noise , liekeba tyre air valve or even more /Marian

[ozvtr]

Unfortunately that test will only tell you if there is no refrigerant in the system at all.
Even a low charge will cause oil and refrigerant to hiss out. Which wont tell you much.
However, if you do get nothing out...well, you'll know what your problem is!

[northrol]

This sounds interesting … I might try this for starts. Thank you

[northrol]

Unfortunately that test will only tell you if there is no refrigerant in the system at all.
Even a low charge will cause oil and refrigerant to hiss out. Which wont tell you much.
However, if you do get nothing out...well, you'll know what your problem is!

So if the system is empty nothing will happen, correct?

[ozvtr]

Yes. When you push the center pin of the Schrader valve nothing will happen if there is no refrigerant in the system. You may get a tiny puff but that will be it.

However, if there is any refrigerant in the system, you will get a rush of gas (and maybe some oil). Unfortunately that doesn't tell you how much refrigerant is in the system.